Propellant explosive



Patented June 2, 1931 WALTER. O. SNELLING, OI ALLENTO WN,

PENNSYLVANIA, ASSIGNOIB. TO TROJAN POWDER. COMPANY, OF NEW YORK, N. Y ACORPORATION OF NEW YORK PBOPELLANI. EXPLOSIVE Il'o Drawing.

My invention relates to propellant explosives, of the smokeless powdertype, and its object is to produce an improved smokeless and flashlesspro ellant containing nitrostarch. This app ication is a continuation inpart of my application Serial No. 47 9,097 for improvements inpropellant explosives filed June 20, 1921.

Efforts have heretofore been made to prepare smokeless powder fromnitrostarch by colloidization, the nitrostarch being dissolved in asuitable solvent to form a colloid mass, and this colloid mass beingthen admixed with suitable inorganic oxidizin agents, such as nitrate ofsoda, nitrate o ammonia, and the like. I have discovered that valuablesmokeless powders may be made from nitrostarch, desensitized sufiicientlto be non-detonating, but preserving the s1ze and shape of the originalstarch granules. I have found further that in employing nitrostarch inthe form of' individual grains, I may successfully employ in connectiontherewith a compound which at the moment of burning will reduce theflame temperature, rendering the explosive substantially flashless. Ihave found also that.

certain organic or inorganic nitrates, partic ularl guanidine nitrate,when present in sufiicient amounts are satisfactory temperature-reducingagents.

As an illustration of one method of preparing an explosive embodying myinvention, I instance the following procedure:

To parts of nitrated starch in the form of the separate nitrated grainsof a vegetable starch, I add 37 parts of guanidine nitrate in the formof a fine crystal meal or of fine particles obtained by grinding, andthoroughly mix. I then bring about surface colloidization of thenitrostarch granules in the manner set forth in U. S. Letters Patent No.1,310,969, issued to me, as as signer, July 22, 1919, employing as thecolloiding agent, say, 37- parts of commercial liquid trinitrotoluene.By this procedure, I obtain an intimate mixture of the desensitizednitrostarch 'ranules in their original physical form, a mixed with thetemperature-reducing agent, which product I Application filed February19, 1926. Serial No. 89,418.

can then press in molds to secure grains of the sizes and shapes used inthe reparation of ordinary smokeless powder. hese grains may at first besomewhat friable, but after standing for some hours, the grains ain instrength and become quite tough. I desired, this period of aging may bematerially shortened by a special hardening treatment, the grains beingexposed to a temperature of or higher, for from thirty minutes to anhour.

I have also employed as a colloidin agent a mixture of liquidtrinitrotoluene an nitroglycerin. In this instance, I proceed asdescribed in the foregoing paragraph and prefer to use the ingredientsin the following proportions: 60 parts of nitrostarch 20 parts ofguanidine nitrate, 10 parts of liquid trinitrotoluene, and 10 parts ofnitroglycerin.

Instead of desensitizing the nitrostarch granules by surfacecolloidization, I may employ oil or wax as a desensitizing agent. Forexample, I may take 15 parts of nitrated starch and mix with this 2parts of molten paraflin wax, thereafter thoroughly incorporating thedesensitized nitrostarch so produced with 83 parts of a suitabletemperature-reducing agent, such as 'guanidine nitrate. As the wax hasagglomerating as .Well as desensitizing properties, the product may bepressed into grains or particles of any desired size or shapes. In thiscase, as in that previously given, the nitrostarch granules aresufliciently desensitized to be rendered non-detonating, and the resultis a highly satisfactory smokeless and flashless propellant explosive.

Instead of paraffin wax as the desensitizing agent, I may desensitizethe nitrostarch with a suitable oil, such, for example, as a mineraloil, and add an agglutinant, such as shellac or coumarone resin,-insuflicient quantity to bind together the granules of starch and theparticles of the nitrate to form a coherent mass and permit moldi 'ginto grains. Suflicient oil is used to render the nitrostarchnon-detonating. For example, I have obtained satisfactory results byusing an'amount of oil equal to] 10% of the weight of the ,nitrostarchused, but I do stearic acid, Japan wax, or other equivalent not wish tobe limited to this proportion, material,- Vegetable, animal or mineraloil as the proportions are capable o variation or oily, materials may beemployed as the So also with agglutinant, various propordesensitizingagent. The colloiding agent, tions may be used. \Vith coumarone resin, Iwhere used, may be other organic nitrates have successfully employed anamount thereor organic nitro bodies than the trinitrotolof equal to byweight of the finished uene and nitroglycerin mentioned, such for duct,example as dinitrotoluene, nitrobenzene, and

In em loying nitrostarch desensitized by mononitronaphthalene.Amylacetate, acemeans of oil, it is not absolutely essential tone or thelike, may also be used. It will that a special agglutinant be'employed.For also be understood that I ma use anyecusexample, using 12 partsoil-desensitized nitomary stabilizing agent, suc as dip nyltrostarch and88 parts guanidine nitrate, the amine, urea or urethane. latter inredient being in slightly moist con- The compacting of my product intograins dition, t e mixture can be compressed at a may be brought abouteither through the high pressure to form dense grains, and action ofpressure alone (as in the manufacserve as an embodiment of my invention.ture of ordinary black powder) or through The proportions of theingredients may the agglutinating effect of superficial colbe variedwithin wide limits, particularly loidization, as described in my PatentNo. with reference to the relative percentages 1,310,969, heretoforereferred to, or through of nitrostarch and guanidine nitrate. The theaddition of a specific agglutinant as nitrostarch should preferablyconstitute hereinbefore described. In any case, the from 10% to of thefinished powder, nitrostarch granules are rendered non-detbut for somepurposes it is conceiva le that onating, are preserved in their originalsatisfactory results may be obtained outside form, and are employed witha suitable of this range. I prefer to use from 50% to oxidizing agent toobtain the smokeless and 90% of guanidine nitrate, but in some flashlesspropellant as described. instances less could be used. The examples Iclaim: heretofore given indicate preferred percent- 1. A propellantexplosive comprising ages of colloiding desensitizing' andagnitrostarch, desensitized by surface colloidiglutinizing agents, butthese also may be zation, and guanidine nitrate. varied in amount, thequantities required in 2. A smokeless and flashless powder comanyparticular case being sufficiently indi- ,prising desensitizednitrostarch and a temcated to the explosives chemist by thepurperature-reducing agent, the latter being an poses pointed out above.addition product of an amine and nitric For the specific ingredientshereinabove acid. specified, equivalents may be substituted. 3. Asmokeless and fiashlesspowder com- As the temperature-reducing agent,instead prising desensitized nitrostarch and an orof guanidine nitrate,I may employ other ganic temperature-reducing agent, the latternitrates, organic or inorganic, such, for being an addition product ofan amine and example, as urea nitrate or ammonium ninitric acid. trate.The structural formulae of these ni- 4. A smokeless and flashless powdercomtrates are: prising desensitized nitrostarch and a re- Guanidinenitrate NH: C(NH .HNO action product of guanidine and nitric acid.

Urea nitrate O: C(NH .HNO3 Ammonium nitrate NH .HNO Thus, it will beseen that these compounds may be considered to be addition products 5. Asmokeless and flashless powder comprising'desensitized nitrostarch andguanidine nitrate.

' 6. The process of rendering nitrostarch of ammonia or an amine andnitric acid. smokeless and flashless, which comprises For the purposesof the claims, these comthoroughly mixing nitrostarch with guanipoundsand their equivalents will be defined dine nitrate in the form of fineparticles, as addition products of an amine and nitric and thereafteradding a desensitizing agacid, within which phrase the additionprodglutinant and compressing the mixture into net of ammonia and nitricacid (ammonium grains of the desired form. nitrate) is included.Nitroguanidine is also 7, The process of rendering nitrostarchapplicable as a temperature-reducing g n smokeless and flashless, whichcomprises 1 formula is 2- 2, and thoroughly mixing nitrostarch granulestherefore both nitrogllanidine an .gllaniwith guanidine nitrate, andthereafter dine nitrate will be defined in the l im flbringing aboutsurface colloidization of the reaction products of guanidine and nitricnitrostarch granules and compressing the i.

acid. Hydrocellulose may e be used mass into grains of the desired form.place of the other temperature-reducing 8. A smokeless and flashlesspowder comcompounds with satisfactory results. prising desensitizednitrostarch and a tem- As agglutinants, I may use Waxymateperature-reduci'ng agent selected from the rials, such as thoseheretofore indicated, or following group,-guanidine nitrate, am- 1.-

anonium nitrate, urea nitrate, nitroguanime. I

,9. The process of rendering nitrostarch smokeless and fias hless, whichcomprises thoroughly mixing nitrostarch with a material selected fromthe following group,- guanidine nitrate, ammonium nitrate, urea nitrate,nitroguanidine,-and thereafter adding a desensitizing agglutinant andcompressing the mixture into grains of the desired form.

10. The process of rendering nitrostarch smokeless and flashless, whichcomprises sired form.

thoroughly mixing nitrostarch granules with a material selected from thefollowing group,-guanidine nitrate, ammonium n1- trate, urea nitrate,nitroguanidine,and

thereafter bringing about surface colloid-' ization of the nitrostarehgranules and compressing the mass into grains of the de- WALTER O.SNELLING.-

